Privacy is the claim of individuals, groups or institutions to determine for themselves when, how, and to what extent information about them is communicated to others. Private information is frequently made public or semi-public via emails, blogs and postings to social networking services, such as Facebook, Twitter, LinkedIn and FourSquare, often without foresight as to the consequences of such a divulgence. It has been reported that information publicly posted to social networking services has been used in firing individuals from their employment and has been used by criminals to find targets for burglaries.
Additionally, intentionally divulged information that is intended to be maintained as private is routinely sold to advertisers and information brokers. Moreover, with the proliferation of app usage in mobile devices, additional information is available on the “information market,” including users' location, age, gender, income, ethnicity, sexual orientation and political views. As recently reported by the Wall Street Journal, of 101 popular smartphone apps, 56 transmitted the device ID without the user's consent, 47 sent location information, and 5 sent age, gender and other personally identifiable information to outsiders.